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Microbial Genomics May 2022is an enterohepatic that causes bacteremia and other diseases in humans. While -like strains are isolated from animals, including dog isolates belonging to a recently...
is an enterohepatic that causes bacteremia and other diseases in humans. While -like strains are isolated from animals, including dog isolates belonging to a recently proposed , little is known about the genetic differences between and these animal isolates. Here, we sequenced 43 or -like strains isolated from humans, hamsters, rats and dogs and collected 81 genome sequences of , and other enterohepatic strains from public databases. Genomic comparison of these strains identified four distinct clades (clades I-IV) in '' (HCCM) complex. Among these, clade I corresponds to and represents a human-adapted lineage in the complex. We identified several genomic features unique to clade I. They include the accumulation of antimicrobial resistance-related mutations that reflects the human association of clade I and the larger genome size and the presence of a CRISPR-Cas system and multiple toxin-antitoxin and restriction-modification systems, both of which indicate the contribution of horizontal gene transfer to the evolution of clade I. In addition, nearly all clade I strains but only a few strains belonging to one minor clade contained a highly variable genomic region encoding a type VI secretion system (T6SS), which could play important roles in gut colonization by killing competitors or inhibiting their growth. We also developed a method to systematically search for sequences in large metagenome data sets based on the results of genome comparison. Using this method, we successfully identified multiple HCCM complex-containing human faecal metagenome samples and obtained the sequence information covering almost the entire genome of each strain. Importantly, all were clade I strains, supporting our conclusion that is a human-adapted lineage in the HCCM complex.
Topics: Animals; Bacteremia; Cricetinae; Dogs; Helicobacter; Helicobacter Infections; Humans; Rats
PubMed: 35536747
DOI: 10.1099/mgen.0.000830 -
Applied and Environmental Microbiology Nov 2016Helicobacter cinaedi is an emerging opportunistic pathogen associated with infections of diverse anatomic sites. Nevertheless, the species demonstrates fastidious axenic...
UNLABELLED
Helicobacter cinaedi is an emerging opportunistic pathogen associated with infections of diverse anatomic sites. Nevertheless, the species demonstrates fastidious axenic growth; it has been described as requiring a microaerobic atmosphere, along with a strong preference for supplemental H gas. In this context, we examined the hypothesis that in vitro growth of H. cinaedi could be enhanced by coculture with human epithelial cells. When inoculated (in Ham's F12 medium) over Caco-2 monolayers, the type strain (ATCC BAA-847) gained the ability to proliferate under H-free aerobic conditions. Identical results were observed during coculture with several other monolayer types (LS-174T, AGS, and HeLa). Under chemically defined conditions, 40 amino acids and carboxylates were screened for their effect on the organism's atmospheric requirements. Several molecules promoted H-free aerobic proliferation, although it occurred most prominently with millimolar concentrations of l-lactate. The growth response of H. cinaedi to Caco-2 cells and l-lactate was confirmed with a collection of 12 human-derived clinical strains. mRNA sequencing was next performed on the type strain under various growth conditions. In addition to providing a whole-transcriptome profile of H. cinaedi, this analysis demonstrated strong constitutive expression of the l-lactate utilization locus, as well as differential transcription of terminal respiratory proteins as a function of Caco-2 coculture and l-lactate supplementation. Overall, these findings challenge traditional views of H. cinaedi as an obligate microaerophile.
IMPORTANCE
H. cinaedi is an increasingly recognized pathogen in people with compromised immune systems. Atypical among other members of its bacterial class, H. cinaedi has been associated with infections of diverse anatomic sites. Growing H. cineadi in the laboratory is quite difficult, due in large part to the need for a specialized atmosphere. The suboptimal growth of H. cinaedi is an obstacle to clinical diagnosis, and it also limits investigation into the organism's biology. The current work shows that H. cinaedi has more flexible atmospheric requirements in the presence of host cells and a common host-derived molecule. This nutritional interplay raises new questions about how the organism behaves during human infections and provides insights for how to optimize its laboratory cultivation.
Topics: Aerobiosis; Caco-2 Cells; Coculture Techniques; Epithelial Cells; HeLa Cells; Helicobacter; Helicobacter Infections; Humans; Hydrogen; Lactic Acid
PubMed: 27613684
DOI: 10.1128/AEM.01943-16 -
Frontiers in Microbiology 2024is a genus of spiral-shaped Gram-negative enterohepatic bacteria whose members are capable of causing bacteremia in humans. One of the poorly studied members of this... (Review)
Review
is a genus of spiral-shaped Gram-negative enterohepatic bacteria whose members are capable of causing bacteremia in humans. One of the poorly studied members of this genus is the bacterium . This microorganism was first isolated from human fecal samples in 1984. Although it was long considered to be associated with only immunocompromised patients, more evidence in recent years has implicated in causing serious pathologies in immunocompetent populations. In addition, is also reported to be associated with a few chronic or severe illnesses, such as atherosclerosis, which in turn can lead to the development of other cardiovascular pathologies: one of the leading causes of mortality worldwide. often goes unnoticed in standard diagnostic methods due to its slow growth under microaerobic conditions. This often leads to significant underdetection and hence undermines the role of this bacterium in the pathogenesis of various diseases and the extent of its spread in humans. In this review, we have compiled information on pathologies associated with , the occurrence of the bacterium in humans and animals, and the latest developments in diagnosing the bacterium and treating associated diseases.
PubMed: 38650874
DOI: 10.3389/fmicb.2024.1371717 -
PloS One 2017Helicobacter cinaedi is associated with nosocomial infections. The CRISPR-Cas system provides adaptive immunity against foreign genetic elements. We investigated the...
Helicobacter cinaedi is associated with nosocomial infections. The CRISPR-Cas system provides adaptive immunity against foreign genetic elements. We investigated the CRISPR-Cas system in H. cinaedi to assess the potential of the CRISPR-based microevolution of H. cinaedi strains. A genotyping method based on CRISPR spacer organization was carried out using 42 H. cinaedi strains. The results of sequence analysis showed that the H. cinaedi strains used in this study had two CRISPR loci (CRISPR1 and CRISPR2). The lengths of the consensus direct repeat sequences in CRISPR1 and CRISPR2 were both 36 bp-long, and 224 spacers were found in the 42 H. cinaedi strains. Analysis of the organization and sequence similarity of the spacers of the H. cinaedi strains showed that CRISPR arrays could be divided into 7 different genotypes. Each genotype had a different ancestral spacer, and spacer acquisition/deletion events occurred while isolates were spreading. Spacer polymorphisms of conserved arrays across the strains were instrumental for differentiating closely-related strains collected from the same hospital. MLST had little variability, while the CRISPR sequences showed remarkable diversity. Our data revealed the structural features of H. cinaedi CRISPR loci for the first time. CRISPR sequences constitute a valuable basis for genotyping, provide insights into the divergence and relatedness between closely-related strains, and reflect the microevolutionary process of H. cinaedi.
Topics: Clustered Regularly Interspaced Short Palindromic Repeats; Evolution, Molecular; Genetic Loci; Genetic Variation; Genomics; Helicobacter; Multilocus Sequence Typing
PubMed: 29028814
DOI: 10.1371/journal.pone.0186241 -
Journal of Infection and Chemotherapy :... Sep 2014Helicobacter cinaedi was first isolated from rectal cultures from homosexual men in 1984. In the 1980s to mid 1990s, the microorganism was mainly isolated from samples... (Review)
Review
Helicobacter cinaedi was first isolated from rectal cultures from homosexual men in 1984. In the 1980s to mid 1990s, the microorganism was mainly isolated from samples from homosexual men or immunocompromised patients; however, during the last two decades, H. cinaedi has been isolated from immunocompromised and from immunocompetent individuals worldwide. In Japan, the isolation of this microorganism was first reported in 2003. Since then, many cases have been reported in hospitals across the country. Despite many reports, the etiological properties and pathogenicity of H. cinaedi remain elusive; however, we are increasingly able to recognize some of the features and the clinical relevance of infection. In particular, a long incubation period is essential for detection in an automatic blood culture system and many of the recent isolates are resistant to both macrolides and quinolones. Furthermore, there is an association between infection and severe or chronic illnesses, such as meningitis or arteriosclerosis, in addition to mild diseases such as fever, abdominal pain, gastroenteritis, proctitis, diarrhea, erysipelas, cellulitis, arthritis, and bacteremia. In this review, we introduce the current knowledge and our latest findings relating to H. cinaedi.
Topics: Animals; Communicable Diseases; Helicobacter; Helicobacter Infections; Humans
PubMed: 25022901
DOI: 10.1016/j.jiac.2014.06.007 -
Gut Pathogens Apr 2021Helicobacter cinaedi are motile, gram-negative spiral rods with a natural reservoir in the intestinal tract of hamsters and rhesus monkeys. In humans, H. cinaedi has...
BACKGROUND
Helicobacter cinaedi are motile, gram-negative spiral rods with a natural reservoir in the intestinal tract of hamsters and rhesus monkeys. In humans, H. cinaedi has been reported in different human infections like fever, abdominal pain, gastroenteritis, proctitis, diarrhoea, erysipelas, cellulitis, arthritis, and neonatal meningitis typically diagnosed by positive blood cultures. Even though H. cinaedi has been detected from human blood and stool the entry of H. cinaedi into the blood stream was undocumented until quite recently. The use of pulse-field gel electrophoresis (PFGE) demonstrated that stool- and blood-derived H. cinaedi strains were consistent.
CASE PRESENTATION
Here, we describe a rare Danish case of H. cinaedi bacteraemia in an immunocompetent 44-year-old male with diarrhoea. We isolated H. cinaedi from a blood culture taken at admission, and from a FecalSwab taken at day six despite ongoing antibiotic therapy. Next, we made a genetic comparison of both isolates by use of Multi-locus sequence typing (MLST)- and Single nucleotide polymorphism (SNP)-analysis. The two isolates were identical with zero SNPs and by use of MLST the isolate was identified as a novel ST20, confirming previous data of the intestinal tract as a route of H. cinaedi bacteraemia. The results of our AST showed a resistance pattern with higher MICs for ciprofloxacin and clarithromycin than for ampicillin, amoxicillin, gentamicin, and imipenem. The patient was cured with targeted therapy with pivampicillin; however, the primary source of transmission was unknown.
CONCLUSIONS
In conclusion, this case of H. cinaedi bacteraemia secondary to enterocolitis in an immunocompetent patient provide clear evidence that one route of infection occurs through translocation from the intestinal tract to the bloodstream. Helicobacter cinaedi from blood and faeces were identical with a novel ST20, resistant to ciprofloxacin and clarithromycin however, the patient was cured with oral pivampicillin.
PubMed: 33888153
DOI: 10.1186/s13099-021-00422-8 -
Antibiotics (Basel, Switzerland) Nov 2012Helicobacter cinaedi causes infections, such as bacteremia, diarrhea and cellulitis in mainly immunocompromised patients. This pathogen is often problematic to analyze,... (Review)
Review
Helicobacter cinaedi causes infections, such as bacteremia, diarrhea and cellulitis in mainly immunocompromised patients. This pathogen is often problematic to analyze, and insufficient information is available, because it grows slowly and poorly in subculture under a microaerobic atmosphere. The first-choice therapy to eradicate H. cinaedi is antimicrobial chemotherapy; however, its use is linked to the development of resistance. Although we need to understand the antimicrobial resistance mechanisms of H. cinaedi, unfortunately, sufficient genetic tools for H. cinaedi have not yet been developed. In July 2012, the complete sequence of H. cinaedi strain PAGU 611, isolated from a case of human bacteremia, was announced. This strain possesses multidrug efflux systems, intrinsic antimicrobial resistance mechanisms and typical mutations in gyrA and the 23S rRNA gene, which are involved in acquired resistance to fluoroquinolones and macrolides, respectively. Here, we compare the organization and properties of the efflux systems of H. cinaedi with the multidrug efflux systems identified in other bacteria.
PubMed: 27029418
DOI: 10.3390/antibiotics1010029 -
Acta Medica Okayama Apr 2018A 65-year-old Japanese man with bilateral carotid atherosclerosis presented with right neck pain and fever. Contrast-enhanced computed tomography suggested carotid...
A 65-year-old Japanese man with bilateral carotid atherosclerosis presented with right neck pain and fever. Contrast-enhanced computed tomography suggested carotid arteritis, and carotid ultrasonography showed an unstable plaque. The patient developed a cerebral embolism, causing a transient ischemic attack. Helicobacter cinaedi was detected in blood culture, and H. cinaedi-associated carotid arteritis was diagnosed. Empirical antibiotic therapy was administered for 6 weeks. After readmission for recurrent fever, he was treated another 8 weeks. Although the relationship between H. cinaedi infection and atherosclerosis development remains unclear, the atherosclerotic changes in our patient's carotid artery might have been attributable to H. cinaedi infection.
Topics: Aged; Anti-Bacterial Agents; Arteritis; Bacteremia; Carotid Artery Diseases; Ceftriaxone; Helicobacter; Helicobacter Infections; Humans; Male; Meropenem; Thienamycins
PubMed: 29674769
DOI: 10.18926/AMO/55861 -
Internal Medicine (Tokyo, Japan) Apr 2018
PubMed: 29279504
DOI: 10.2169/internalmedicine.9721-17 -
Journal of Clinical Microbiology Dec 2012Helicobacter cinaedi is the most frequently reported enterohepatic Helicobacter species isolated from humans. Earlier research suggested that certain patients with H....
Helicobacter cinaedi is the most frequently reported enterohepatic Helicobacter species isolated from humans. Earlier research suggested that certain patients with H. cinaedi infection may remain undiagnosed or incorrectly diagnosed because of difficulties in detecting the bacteria by conventional culture methods. Here, we report a nested PCR assay that rapidly detects the cytolethal distending toxin gene (cdt) of H. cinaedi with high specificity and sensitivity. Specificity of the assay was validated by using different species of Helicobacter and Campylobacter, as well as known H. cinaedi-positive and -negative samples. The sensitivity of detection for the cdt gene in the assay was 10(2) CFU/ml urine or 10(2) CFU/10(5) infected RAW 264.7 cells. In an H. cinaedi-infected mouse model, the cdt gene of H. cinaedi was effectively detected via the assay with urine (6/7), stool (2/3), and blood (2/6) samples. Importantly, it detected H. cinaedi in blood, urine, and stool samples from one patient with a suspected H. cinaedi infection and three patients with known infections. The assay was further used clinically to follow up two H. cinaedi-infected patients after antibiotic treatment. Stool samples from these two patients evaluated by nested PCR after antibiotic therapy showed clearance of bacterial DNA. Finally, analysis of stool specimens from healthy volunteers showed occasional positive reactions (4/30) to H. cinaedi DNA, which suggests intestinal colonization by H. cinaedi in healthy subjects. In conclusion, this nested PCR assay may be useful for the rapid diagnosis, antimicrobial treatment evaluation, and epidemiological study of H. cinaedi infection.
Topics: Adult; Aged; Animals; Bacterial Toxins; Bacteriological Techniques; Blood; Carrier State; Disease Models, Animal; Feces; Female; Helicobacter; Helicobacter Infections; Humans; Male; Mass Screening; Mice; Middle Aged; Polymerase Chain Reaction; Sensitivity and Specificity; Urine; Young Adult
PubMed: 23015666
DOI: 10.1128/JCM.01622-12